Chip cards (also referred to as smart cards) may include an integrated chip card module (also referred to as chip module or smart card module) having at least one chip. The chip card module may be arranged in a chip card body.
A chip card can be a so-called “dual interface” chip card (DIF chip card), i.e. the chip card may include both a chip contact structure, e.g. chip contact pads, arranged on the chip card module, for example, for electrically connecting the chip card to a device, for example to a card reader, and an apparatus for wireless communication, which may use induction for data interchange and energy supply of the chip card, for example by the use of radio waves. The apparatus for wireless communication chip also be referred to as an interface for wireless data transmission, a wireless interface, or a CL interface.
The wireless interface may include, for example, an antenna arranged in the chip card body. Said antenna may also be referred to as chip card body antenna or booster antenna. The booster antenna may be designed in such a way that contactless data transfer between the booster antenna and an external device may take place. In other words, the booster antenna may be designed in such a way that it can receive and transmit electromagnetic information and energy from and to outside the chip card. In addition, the wireless interface may include an antenna in the chip card module. The booster antenna may be inductively coupled to the antenna of the chip card module or may couple inductively. In other words, the antenna of the chip card module may be designed in such a way that it can perform information and energy interchange by induction with the booster antenna. The antenna of the chip card module may additionally be electrically conductively connected to the chip.
Therefore, contactless data transfer may be enabled between the external device and the chip (from the external device to the chip and/or from the chip to the external device) by the booster antenna, the antenna in the chip card module, and the electrically conductive connection to the chip.
The technology of the antenna arranged on the chip card module for inductive coupling to the booster antenna is also referred to as coil-on-module (CoM).
In CoM-modules, the antenna may be designed to match an input capacitance of the chip.
For example, in combination with the booster antenna, the CoM module may be used for realizing a reliable dual interface (DIF) chip card.
In case of an application requiring contactless communication only, a module may be equipped with coil windings on both sides. Up to now, only coil structures may be used.